We have always thrived on a low carbohydrate and low sugar diet. We evolved over millions of years as hunter-gatherers, we ate the food available to us in nature by hunting, fishing and gathering all the edible foods we could find. These foods did not include pure starch in the form of bread or pasta nor any food with added sugar.
Today most foods that come in packet or carton have added sugar, fat or both.
In the 80s, the fear of fat gripped the western world. Low-fat products popped up everywhere. Brands across the world removed the fat from food products and the fat was replaced by versions of added sugar.
This is the exact time in history that our disastrous epidemic of obesity and diabetes began.